Type 1 diabetes (T1D), with its array of complications, increases the risk of mortality compared to the general population. Although advances in treatment since the 1980s have significantly reduced long-term morbidity, recent estimates of T1D mortality remain twice as high as the general population. The Allegheny County Insulin-dependent diabetes mellitus Registry (ACIR) consists of 1,075 persons diagnosed between 1965 and 1979 with T1D before 18 years of age in Allegheny County, Pennsylvania. The current research proposal aims to survey this cohort to determine: 1) population-based mortality rates for long-term T1D (25-40 yr duration) and factors associated with increased mortality;2) time trends of total and cause-specific mortality by diagnosis cohort;and 3) the prevalence of long-term diabetes complications in a population based cohort and factors associated with increased risk of morbidity. Initially, we will re-contact this population by mail with a health survey to ascertain vital status as of 1 January 2007. We will search both the Social Security Death Index and the National Death Index for persons we are unable to contact. We will calculate overall, sex-, and race-specific mortality rates and survival curves to examine risk differences by race and gender, and cumulative survival rates up to 40 years duration of diabetes. We will also calculate standardized mortality ratios based on local and national mortality statistics for the general population. Next, we will explore time trends of total and cause-specific mortality by diagnosis cohort, assessing variations by race and gender. Using regression analysis, we will examine an interaction between cohort and time to death to explore differential time trends in mortality. We will explore whether rates have continued to decline by diagnosis cohort between 2000 and 2007 as we previously reported up to 1999. We will also examine whether patterns in causes of death have changed over time. Finally, we will determine the prevalence of, and factors associated with, long-term diabetes complications in this large population-based cohort through a cross-sectional analysis of survey data. Based on surveys from the Pittsburgh EDC Study, we have developed a detailed survey that includes information on physician-diagnosed complications, diabetes treatment, and demographic and socioeconomic factors. Our ultimate goal is to determine factors associated with long-term morbidity and mortality in T1D that can be the focus of prevention efforts. Ideally, we expect mortality rates in T1D patients to continue to approach those of the general population.